One of the conventional techniques of an ultrasonograph including a touch panel-equipped display is described in Patent Document 1 below. FIG. 24 shows a conventional display example in which a drag operation is used to change the content of an ultrasonic tomographic image displayed on the touch panel-equipped display. The display screen is divided into an ultrasonic image area A1 which displays an ultrasonic image P and an operating part display area A2 which displays buttons for selection of a change of the ultrasonic image P (Gain, Depth, Color, Dop, and M in the drawing). When the operator touches the ultrasonic image area A1 with a finger F and drags after selecting a desired change by selectively touching one of the buttons displayed in the operating part display area A2, the display image P is changed according to the selected change and the drag direction. Another way of drag can be also used in measurement of the distance between the drag start position and the drag end position (for example, fetal head size) and the like.
A conventional ultrasonograph in which various image parameters of the ultrasonographic image displayed on a monitor can be changed with input devices includes: a monitor which displays a diagnostic image together with names and values of setting parameters; and various types of input devices for changing the image parameters. The input devices generally include hard keys such as a trackball, a key switch, a slide resistor, and an encoder knob and further include an input device provided with a multipurpose touch panel as a sub-display (see Patent Document 2) or a monitor provided with a touch panel so that input and display of images are performed on a same plane (see Patent Documents 3 and 4).
Patent Document 1: Japanese Patent Application Publication No. 2003-169798 (paragraph No. 0042)
Patent Document 2: Japanese Patent Application Publication No. H10-248843 (FIG. 1)
Patent Document 3: Japanese Patent Application Publication No. 2002-336250 (FIG. 3)
Patent Document 4: Japanese Patent Application Publication No. 2006-26256 (FIG. 2)
However, in the aforementioned conventional technique shown in FIG. 24, the finger F touches the ultrasonic image area A1 of the display screen and is dragged thereon. Accordingly, the ultrasonic image area A1 gets dirty with a fingerprint FP or a scratch D, thus making it hard to see the ultrasonic image P.